Driving slower saves gas, true or false?

However, this is a misconception and is not based on the manufacturer's instructions.

When buying a car, choosing a fuel-efficient car is very important. However, the way you drive also significantly affects the fuel efficiency of the car. So, how to drive to achieve the highest fuel efficiency?

There is no general rule that applies to all types of vehicles when it comes to driving speed to save fuel. Each vehicle with its own specifications will have an optimal speed to reduce fuel consumption. Driving too slow or too fast can increase fuel consumption unnecessarily.

Why going slow doesn't save gas?

When driving too slowly, the engine will usually rotate at a low speed, usually between 1,000 and 3,000 rpm. When the vehicle is running in a low gear, the engine speed will be higher per km. This results in more fuel being consumed to burn for each rotation cycle.

Additionally, if the vehicle is traveling at a higher speed, it will shift into a higher gear, but still maintain the engine speed between 1,000 and 3,000 rpm. When the engine operates at this speed for a long time, it will result in less fuel consumption. However, this also comes with increased drag.

Specifically, air resistance increases with the square of the speed. For example, when driving at 80km/h, air resistance is 8 times greater than when driving at 40km/h. This means that when the speed is doubled, air resistance increases by 4 times. This means that the engine has to work harder to overcome air resistance, and therefore, fuel consumption will increase.

To save fuel, drivers should drive their vehicles at speeds ranging from 48 to 80 km/h. At this time, air resistance is low and the engine should be shifted to a higher gear to achieve the optimal km/rev figure. Unless the vehicle is aerodynamically designed, most vehicles will not achieve the optimal fuel economy/km figure when traveling at speeds between 96 and 104 km/h.

So drivers need to understand that driving at low speeds, such as 10 mph, for a long distance is actually not more fuel efficient than driving at high speeds, such as 90 mph.

Mistakes to avoid when driving to save fuel

Avoid sudden acceleration or deceleration: Do not step on the accelerator pedal to accelerate quickly and then brake suddenly, as this behavior is harmful to the engine and increases fuel consumption by up to 4 times.

Limit the use of air conditioning too much: Do not overuse the air conditioner, especially when the car is moving slowly, because this increases fuel consumption. Experts recommend reducing the use of air conditioning when the outdoor temperature is above 26.6 degrees Celsius to save about 10-15% of fuel.

Refuel when out of gas: To avoid damaging your vehicle, do not let the vehicle run out of gas before refueling. The optimal solution is to refuel when the fuel gauge is less than half full.